A coating defect removal process and an infrared cut-off filter

Abstract

This invention discloses a coating defect removal process and an infrared cutoff filter. The process includes the following steps: when coating surface A of the infrared cutoff filter, heating the first vacuum chamber of surface A to generate a first haze in the high-refractive-index material film layer of surface A; when coating surface B of the infrared cutoff filter, heating the second vacuum chamber of surface B to generate a second haze in the high-refractive-index material film layer of surface B. By increasing the heating temperature of the first and second vacuum chambers to corresponding temperature thresholds during the coating of the low-reflection film on surface A and the multilayer film on surface B, the high-refractive-index material of the low-reflection film on surface A and the multilayer film on surface B changes from an amorphous state to a crystalline state, generating corresponding hazes, thus removing "star-like" coating defects. Furthermore, the generated haze does not affect visual perception, improving the yield of the camera module.

Description

Technical Field

[0001] This invention relates to the field of camera module coating technology, and in particular to a coating defect removal process and an infrared cutoff filter. Background Art

[0002] Infrared cut-off filters are often used in camera modules to filter out infrared light between 700nm and 1000nm, while maintaining high transmittance of visible light between 420nm and 680nm, thereby improving image quality. After coating on both sides A and B, the average transmittance of visible light is usually above 98%, making the entire product appear very transparent. However, due to the high transmittance, many "star-like" defects within the film layer are clearly visible under a 20x microscope.

[0003] Therefore, existing infrared cut-off filters have many "star-like" defects in the film layer after coating. In order to improve the yield of camera modules, there is an urgent need for a process to remove the "star-like" defects in the film layer. Summary of the Invention

[0004] Existing infrared cut-off filters have many "star-like" defects after coating, which affects the yield of camera module products.

[0005] To address the aforementioned issues, a coating defect removal process and an infrared cutoff filter are proposed. By increasing the heating temperatures of the first and second vacuum chambers to corresponding temperature thresholds during the deposition of the low-reflection film on side A and the multilayer film on side B, the high-refractive-index materials of the low-reflection film on side A and the multilayer film on side B are transformed from an amorphous state to a crystalline state, generating corresponding haze. This process removes the "star-like" coating defects, and the generated haze does not affect vision, thereby improving the yield of the camera module.

[0006] In a first aspect, a coating defect removal process includes the following steps:

[0007] When depositing the infrared cut-off filter A, the first vacuum cavity of the A surface is heated so that the high refractive index material film layer of the A surface produces a first haze.

[0008] When depositing the B-side of the infrared cutoff filter, the second vacuum cavity of the B-side is heated to produce a second haze in the high refractive index material film layer of the B-side.

[0009] In conjunction with the coating defect removal process described in this invention, in a first possible embodiment, the step of: heating the first vacuum cavity of the A-side during the deposition of the infrared cut-off filter A-side to induce a first haze in the high-refractive-index material film layer of the A-side, includes the following steps:

[0010] Obtain the first number of high refractive index material film layers on surface A of the infrared cutoff filter;

[0011] The first vacuum cavity is heated according to the first number of film layers so that the high refractive index material film layer on surface A changes from an amorphous state to a crystalline state;

[0012] The high refractive index material is TiO2.

[0013] In conjunction with the first possible embodiment of the present invention, in the second possible embodiment, the step of heating the first vacuum cavity according to the first number of film layers, so that the high refractive index material film layer on surface A changes from an amorphous state to a crystalline state, includes the following steps:

[0014] Obtain the first reference heating temperature of the first vacuum cavity;

[0015] Based on the first reference heating temperature, the first vacuum cavity is continued to be heated until the first temperature threshold is reached;

[0016] The total number of the first film layers ranges from 3 to 5 layers, the first haze is less than the haze threshold, and the first temperature threshold is 250 degrees Celsius.

[0017] In conjunction with the second possible embodiment of the present invention, and in the third possible embodiment, the haze threshold is 0.4%.

[0018] In conjunction with the coating defect removal process described in this invention, in a fourth possible embodiment, the step of: heating the second vacuum cavity of the B-side during the deposition of the infrared cut-off filter B-side to induce a second haze in the high-refractive-index material film layer of the B-side, includes the following steps:

[0019] The number of the second film layers of the high refractive index material film layer on the B side of the infrared cut-off filter is obtained;

[0020] The second vacuum cavity is heated according to the second number of film layers so that the high refractive index material film layer on the B side changes from an amorphous state to a crystalline state;

[0021] The high refractive index material is TiO2.

[0022] In conjunction with the fourth and fifth possible embodiments of the present invention, the step of heating the second vacuum cavity according to the number of the second film layers to convert the high refractive index material film layer on the B-side from an amorphous state to a crystalline state includes the following steps:

[0023] Obtain the second reference heating temperature of the second vacuum chamber;

[0024] Based on the second reference heating temperature, the second vacuum cavity is heated further until the second temperature threshold is reached;

[0025] The total number of the second film layers ranges from 16 to 22, the second haze is less than the haze threshold, and the second temperature threshold is 170 degrees Celsius.

[0026] In conjunction with the fifth and sixth possible embodiments of the present invention, the haze threshold is 0.4%.

[0027] Secondly, an infrared cut-off filter, employing the coating defect removal process of the first aspect, includes:

[0028] Substrate glass;

[0029] A low-reflection film deposited on surface A of the substrate glass;

[0030] as well as

[0031] A multilayer thin film deposited on the B-side of the substrate glass;

[0032] In the process of depositing the low-reflection film, the first vacuum cavity on surface A is heated so that the high-refractive-index material film on surface A produces a first haze.

[0033] During the deposition of multilayer thin films, the second vacuum cavity on side B is heated to induce a second haze in the high refractive index material film layer on side B.

[0034] In conjunction with the infrared cut-off filter described in the second aspect of the present invention, in a first possible embodiment, when the first haze is generated, the first vacuum cavity is heated according to the first number of film layers so that the high refractive index material film layer on surface A is converted from an amorphous state to a crystalline state, and the first vacuum cavity is heated further on the basis of the first reference heating temperature until the first temperature threshold is reached.

[0035] The total number of the first film layers ranges from 3 to 5.

[0036] The first temperature threshold is 250 degrees Celsius.

[0037] In conjunction with the infrared cut-off filter described in the second aspect of the present invention, in a second possible embodiment, when the second haze is generated, the second vacuum cavity is heated according to the number of second film layers so that the high refractive index material film layer on the B side is converted from an amorphous state to a crystalline state, and the second vacuum cavity is heated further on the basis of the second reference heating temperature until the second temperature threshold is reached.

[0038] The total number of the second film layers ranges from 16 to 22.

[0039] The second temperature threshold is 170 degrees Celsius.

[0040] By implementing the coating defect removal process and infrared cut-off filter described in this invention, the heating temperatures of the first and second vacuum chambers are increased to corresponding temperature thresholds during the deposition of the low-reflection film on side A and the multilayer film on side B. This causes the high-refractive-index materials of the low-reflection film on side A and the multilayer film on side B to transform from an amorphous state to a crystalline state, generating corresponding haze. This removes the "star-like" coating defects, and the generated haze does not affect vision, thus improving the yield of the camera module. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a first schematic diagram of the coating defect removal process of the present invention;

[0043] Figure 2 This is a second schematic diagram of the coating defect removal process of the present invention;

[0044] Figure 3 This is a third schematic diagram of the coating defect removal process of the present invention;

[0045] Figure 4 This is the fourth schematic diagram of the coating defect removal process of the present invention;

[0046] Figure 5 This is the fifth schematic diagram of the coating defect removal process of the present invention;

[0047] Figure 6 This is a schematic diagram of the infrared cutoff filter structure of the present invention; Detailed Implementation

[0048] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are all within the scope of protection of this invention.

[0049] Existing infrared cut-off filters have many "star-like" defects after coating, which affects the yield of camera module products.

[0050] To address the above problems, a coating defect removal process and an infrared cutoff filter are proposed.

[0051] Example 1

[0052] Firstly, a coating defect removal process, such as Figure 1 , Figure 1 This is a first schematic diagram of the coating defect removal process of the present invention; including the following steps:

[0053] Step 100: When depositing the infrared cut-off filter A side, the first vacuum cavity of the A side is heated to produce a first haze in the high refractive index material film layer of the A side; Step 200: When depositing the infrared cut-off filter B side, the second vacuum cavity of the B side is heated to produce a second haze in the high refractive index material film layer of the B side. Preferably, the high refractive index material is TiO2.

[0054] Based on the thin film characteristics of TiO2, during the film formation process, higher temperatures lead to a transformation from an amorphous to a crystalline state, and the grain size increases with increasing temperature. Typically, conventional deposition temperatures are below 120 degrees Celsius, resulting in an amorphous TiO2 film. Light passing through this amorphous film generally propagates in its original direction without scattering. However, as TiO2 begins to crystallize, light passing through the film undergoes various reflections and refractions at the grain boundaries, causing the emitted light to deviate from its original direction, thus producing haze. The larger the grains, the more reflections and refractions occur at the grain boundaries, resulting in higher haze.

[0055] During the coating process of infrared cut-off filters, both sides A and B are coated with alternating layers of high-refractive-index and low-refractive-index materials. The total number of film layers on side A is typically between 7 and 10, with 3 to 5 layers of the high-refractive-index material TiO2. The total number of film layers on side B is typically between 35 and 45, with 16 to 22 layers of the high-refractive-index material TiO2.

[0056] In this embodiment, the temperature can be set to increase the haze on surface A, while the temperature can be set to decrease the haze on surface B. Therefore, the haze threshold can be greater than or equal to the haze threshold.

[0057] Example 2

[0058] In this embodiment, when haze occurs on surface A, such as Figure 2 , Figure 2 This is a second schematic diagram of the coating defect removal process of the present invention; it can be specifically implemented as follows:

[0059] Step 100 includes the following steps: Step 110, obtaining the first number of high refractive index material film layers on the A-side of the infrared cutoff filter; Step 120, heating the first vacuum cavity according to the first number of film layers, so that the high refractive index material film layers on the A-side are transformed from an amorphous state to a crystalline state.

[0060] The first layer of the high refractive index material film on side A can be 3-5 layers. A higher temperature, such as 250 degrees Celsius, is set in the first vacuum chamber, so that the accumulated 3-5 layers of high refractive index material TiO2 will produce relatively more fogging.

[0061] Specifically, when haze is generated, such as Figure 3 , Figure 3 This is a third schematic diagram of the coating defect removal process of the present invention; it can be specifically implemented as follows: Step 120 includes the following steps: Step 121, obtaining the first reference heating temperature of the first vacuum chamber; Step 122, continuing to heat the first vacuum chamber based on the first reference heating temperature until the first temperature threshold is reached; wherein, the total number of the first film layers ranges from 3 to 5 layers; the first temperature threshold is 250 degrees Celsius.

[0062] In this embodiment, the first reference heating temperature is the conventional temperature for heating the vacuum chamber during coating, typically 120 degrees Celsius. Based on this, the first temperature threshold is set to 250 degrees Celsius to generate the first haze and remove "stars".

[0063] Preferably, the first haze is less than the haze threshold; the haze threshold is 0.4%, thereby controlling its impact on transmittance to within 1%, so as to minimize its impact on transmittance.

[0064] Example 3

[0065] In this embodiment, when haze occurs on surface B, such as Figure 4 , Figure 4 This is a fourth schematic diagram of the coating defect removal process of the present invention; it can be specifically implemented as follows: Step 200 includes the following steps: Step 210, obtaining the second number of high refractive index material film layers on the B side of the infrared cut-off filter; Step 220, heating the second vacuum cavity according to the second number of film layers, so that the high refractive index material film layer on the B side changes from an amorphous state to a crystalline state.

[0066] The first layer of the high refractive index material film on the B side can be 16-22 layers. The second vacuum chamber is set at a relatively low temperature, such as 170 degrees Celsius, so that the accumulated 16-22 layers of high refractive index material TiO2 will have relatively large fogging.

[0067] Specifically, when haze is generated, such as Figure 5 , Figure 5This is the fifth schematic diagram of the coating defect removal process of the present invention; it can be specifically implemented as follows:

[0068] Step 220 includes the following steps: Step 221, obtaining the second reference heating temperature of the second vacuum chamber; Step 222, continuing to heat the second vacuum chamber based on the second reference heating temperature until a second temperature threshold is reached; wherein, the total number of the second film layers ranges from 16 to 22 layers; and the second temperature threshold is 170 degrees Celsius.

[0069] In this embodiment, the second reference heating temperature is the conventional temperature for heating the vacuum chamber during coating, typically 120 degrees Celsius. Based on this, the second temperature threshold is set to 170 degrees Celsius to generate the second haze and remove "stars".

[0070] The second haze level is less than the haze threshold; the haze threshold is 0.4%, thus controlling its impact on transmittance to within 1%, minimizing its impact on transmittance.

[0071] By increasing the heating temperatures of the first and second vacuum chambers to the corresponding temperature thresholds during the deposition of the low-reflection film 320 on side A and the multilayer film 330 on side B, the high-refractive materials of the low-reflection film 320 on side A and the multilayer film 330 on side B are converted from an amorphous state to a crystalline state, generating corresponding haze. This removes the "star-like" coating defects, and the generated haze does not affect vision, thus improving the yield of the camera module.

[0072] Example 4

[0073] An infrared cutoff filter employs a coating defect removal process as described in the first aspect, such as... Figure 6 , Figure 6 This is a schematic diagram of the infrared cut-off filter structure of the present invention; it includes: a substrate glass 310, a low-reflection film 320 deposited on the A side of the substrate glass 310, and a multilayer film 330 deposited on the B side of the substrate glass 310.

[0074] Specifically, during the deposition of the low-reflection thin film 320, the first vacuum cavity on surface A is heated to generate a first haze in the high-refractive-index material film layer on surface A; during the deposition of the multilayer thin film 330, the second vacuum cavity on surface B is heated to generate a second haze in the high-refractive-index material film layer on surface B.

[0075] Preferably, when the first haze is generated, the first vacuum cavity is heated according to the first number of film layers so that the high refractive index material film layer on surface A changes from an amorphous state to a crystalline state, and the first vacuum cavity is heated further at the first reference heating temperature until the first temperature threshold is reached.

[0076] The total number of the first film layers ranges from 3 to 5.

[0077] The first temperature threshold is 250 degrees Celsius.

[0078] Preferably, when the second haze is generated, the second vacuum cavity is heated according to the number of second film layers so that the high refractive index material film layer on the B side is converted from an amorphous state to a crystalline state, and the second vacuum cavity is heated further at the second reference heating temperature until the second temperature threshold is reached.

[0079] The total number of the second film layers ranges from 16 to 22.

[0080] The second temperature threshold is 170 degrees Celsius.

[0081] The coating defect removal process and infrared cut-off filter of the present invention, by increasing the heating temperature of the first vacuum chamber and the second vacuum chamber to the corresponding temperature thresholds during the deposition of the low-reflection film 320 on the A side and the multilayer film 330 on the B side, causes the high-refractive materials of the low-reflection film 320 on the A side and the multilayer film 330 on the B side to change from an amorphous state to a crystalline state, respectively generating corresponding haze, removing the "star point" coating defect, and the generated haze does not affect vision, thereby improving the yield of the camera module.

[0082] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coating defect removal process, characterized in that, The steps for removing "star-like" coating defects include: Step 100: When depositing the infrared cut-off filter A, the first vacuum cavity of the A surface is heated so that the high refractive index material film layer of the A surface produces a first haze. Step 100 includes: Step 110, obtaining the first number of high refractive index material film layers on the A-side of the infrared cut-off filter; Step 120, heating the first vacuum cavity according to the first number of film layers, so that the high refractive index material film layers on the A-side are transformed from an amorphous state to a crystalline state. Step 120 includes: Step 121, obtaining a first reference heating temperature of the first vacuum cavity; the first reference heating temperature is 120 degrees Celsius; Step 122, continuing to heat the first vacuum cavity based on the first reference heating temperature until a first temperature threshold is reached; the total number of the first film layers ranges from 3 to 5 layers; the first temperature threshold is 250 degrees Celsius. Step 200: When depositing the infrared cut-off filter B side, the second vacuum cavity of the B side is heated so that the high refractive index material film layer of the B side produces a second haze. Step 200 includes: Step 210, obtaining the second number of high refractive index material film layers on the B-side of the infrared cut-off filter; Step 220, heating the second vacuum cavity according to the second number of film layers, so that the high refractive index material film layers on the B-side are transformed from an amorphous state to a crystalline state; Step 220 includes: Step 221, obtaining a second reference heating temperature for the second vacuum cavity; Step 222, continuing to heat the second vacuum cavity to a second temperature threshold temperature based on the second reference heating temperature; The second reference heating temperature is 120 degrees Celsius; The total number of the second film layers ranges from 16 to 22 layers; The second temperature threshold temperature is 170 degrees Celsius. The first haze level is less than the haze threshold; The second haze level is less than the haze threshold. The haze threshold is 0.4%.

2. The coating defect removal process according to claim 1, characterized in that, The high refractive index material is TiO2.

3. An infrared cut-off filter, employing the coating defect removal process described in claim 1, characterized in that, include: Substrate glass; A low-reflection film deposited on surface A of the substrate glass; as well as A multilayer thin film deposited on the B-side of the substrate glass; In the process of depositing the low-reflection film, the first vacuum cavity on surface A is heated so that the high-refractive-index material film on surface A produces a first haze. During the deposition of multilayer thin films, the second vacuum cavity on side B is heated to induce a second haze in the high refractive index material film layer on side B.

4. The infrared cutoff filter according to claim 3, characterized in that, When the first haze is generated, the first vacuum cavity is heated according to the first number of film layers so that the high refractive index material film layer on surface A changes from an amorphous state to a crystalline state, and the first vacuum cavity is heated further at the first reference heating temperature until the first temperature threshold is reached. The total number of the first film layers ranges from 3 to 5. The first temperature threshold is 250 degrees Celsius.

5. The infrared cutoff filter according to claim 4, characterized in that, When the second haze is generated, the second vacuum cavity is heated according to the second film layer number so that the high refractive index material film layer on the B side is converted from an amorphous state to a crystalline state, and the second vacuum cavity is heated further at the second reference heating temperature until the second temperature threshold is reached. The total number of the second film layers ranges from 16 to 22. The second temperature threshold is 170 degrees Celsius.

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